Referring to FIG. 6 to FIG. 10, conventional bump bonding device and bump bonding method are described below.
FIG. 6 is a perspective view of a bump bonding device for forming a bump on an electronic part 3 by using a gold wire 10.
In the diagram, the electronic part 3 supplied from a tray 10 is fixed on a heated stage 1 by means of a suction collet 10. A capillary 12 is held by an ultrasonic feed unit, and is provided with an ultrasonic wave, and a gold bump is formed on the electrode of the electronic part 3 by the capillary 12 in which the gold wire 13 is passed. After forming bumps on specified positions thereof, the electronic part 3 is stored in a tray 10a by means of the suction collet 11.
FIGS. 7(a)-7(d) are process diagrams showing the bump forming process.
First, at step (a), the gold wire 13 is passed in the capillary 12, a spark is ignited on the tip of the gold wire 13, and a ball is formed on the tip. At next step (b), the capillary 12 is lowered to press on an electrode 14 of the electronic part 3. At this time, an ultrasonic wave is applied to bond the electrode 14 and gold wire 13 (1st bonding). At step (c), consequently, the capillary 12 is lifted, and is lowered again while controlling the loop, and, at step (d), the capillary 12 presses on the gold ball of first bonding, and cuts off the gold wire 13 (2nd bonding).
A regulating section of electronic parts is described in detail below.
FIG. 8 is a plan view of electronic parts regulating section.
As shown in FIG. 8, the regulating section of the bump bonding device is composed of a stage 1 having a suction hole, a regulating pawl 2 movable in the XY direction, and a regulating spring 5 for applying a regulating force in the Y direction of the regulating pawl 2, in which the electronic part 3 moves on the suction hole of the stage 1 by means of the regulating pawl 2, and is regulated in position on the stage 1 by vacuum suction. However, the suction force is insufficient for a tiny electronic part, a regulating section as shown in FIG. 9 is used.
As shown in FIG. 9, the regulating section is composed a stage 1, a plate 4 fixed at an end of the stage 1, a regulating pawl 2 movable in the XY direction, and a regulating spring 5 for applying a regulating force in the Y direction of the regulating pawl 2.
In this regulating section, it is hard to set the regulating pawl parallel to the plate 4, and therefore when regulating the position of the electronic part 3, if a regulating force is applied to the electronic part 3 by the regulating pawl 2, a corner 3a of the electronic part may collide against the plate 4, and the electronic part may be broken.
FIG. 10 is a flowchart showing operation by the conventional electronic parts regulating device.
The electronic part is put on the stage 1 of the bump bonding device, the suction device is turned on, the electronic part is positioned, and, in this state, the electronic part 3 is bonded. In the case of a tiny electronic part, however, the suction hole is not suited to the dimension of the electronic part, or the suction hole located on the regulating track of the electronic part cannot be blocked according to the dimension of the electronic part, and suction errors often took place.
Generally, a tiny electronic part is fragile, and therefore when handling a tiny electronic part, it is required to decrease the impact force when regulating the position to prevent breakage of electronic part. It is hence an object of the invention to present an electronic part of high reliability, free from breakage when positioning the electronic part. Besides, if suction error occurs, the electronic part is likely to be cooled and defective bonding is caused, and, therefore, by preventing suction error, it is also an object of the invention to present an electronic part of high reliability with a lower rate of defective bonding.